Known adjustable bed carriages are generally of three types. One type of adjustable bed carriage includes leg assemblies which are positioned at both ends of a main bed frame. An example of this type of known adjustable bed carriage is disclosed in U.S. Pat. No. 4,023,849 (Bethlen).
A second general type includes extendable linkages at both ends of the main bed frame. For instance, such an adjustable bed carriage is disclosed in U.S. Pat. No. 4,097,939 (Peck et al.).
The other well-known type of adjustable bed carriage includes a base supported by casters, wheels or feet on which legs (or linkages), are positioned, extending upwardly to the main bed frame. U.S. Pat. No. 3,462,772 (Morrison) discloses an example of this general type of known adjustable bed carriage.
Scissor leg assemblies are also known and can provide relative simplicity and generally greater overall strength and stability. However, scissor leg assemblies have not generally been used in adjustable bed carriages, and those that have suffer from some deficiencies. For example, in U.S. Pat. No. 5,613,255 (Bish et al.), an adjustable bed carriage is disclosed in which two scissor leg assemblies support the main bed frame. However, the Bish et al. adjustable bed carriage is relatively complex, involving a relatively large number of components. In particular, the two scissor leg assemblies are shown (in FIGS. 4 and 5 of Bish et al.) to include a number of slidable connections between the scissor leg assemblies and a base and a main bed frame. Such slidable connections should be minimized in order to reduce manufacturing costs.
There is therefore a need for an improved adjustable bed carriage for supporting a main bed frame.